2’’-O-Acetylsprengerinin C

30866036

Background
The inability to have children affects 10% to 15% of couples worldwide. A male factor is estimated to account for up to half of the infertility cases with between 25% to 87% of male subfertility considered to be due to the effect of oxidative stress. Oral supplementation with antioxidants is thought to improve sperm quality by reducing oxidative damage. Antioxidants are widely available and inexpensive when compared to other fertility treatments, however most antioxidants are uncontrolled by regulation and the evidence for their effectiveness is uncertain. We compared the benefits and risks of different antioxidants used for male subfertility. This review did not examine the use of antioxidants in normospermic men.

Objectives
To evaluate the effectiveness and safety of supplementary oral antioxidants in subfertile men.

Search methods
The Cochrane Gynaecology and Fertility (CGF) Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL, and two trials registers were searched on 1 February 2018, together with reference checking and contact with study authors and experts in the field to identify additional trials.

Selection criteria
We included randomised controlled trials (RCTs) that compared any type, dose or combination of oral antioxidant supplement with placebo, no treatment or treatment with another antioxidant, among subfertile men of a couple attending a reproductive clinic. We excluded studies comparing antioxidants with fertility drugs alone and studies that included fertile men attending a fertility clinic because of female partner infertility.

Data collection and analysis
We used standard methodological procedures recommended by Cochrane. The primary review outcome was live birth. Clinical pregnancy, adverse events and sperm parameters were secondary outcomes.

Main results
We included 61 studies with a total population of 6264 subfertile men, aged between 18 and 65 years, part of a couple who had been referred to a fertility clinic and some of whom were undergoing assisted reproductive techniques (ART). Investigators compared and combined 18 different oral antioxidants. The evidence was of ‘low’ to ‘very low’ quality: the main limitation was that out of the 44 included studies in the meta?analysis only 12 studies reported on live birth or clinical pregnancy. The evidence is current up to February 2018.

Live birth: antioxidants may lead to increased live birth rates (OR 1.79, 95% CI 1.20 to 2.67, P = 0.005, 7 RCTs, 750 men, I2 = 40%, low?quality evidence). Results suggest that if in the studies contributing to the analysis of live birth rate, the baseline chance of live birth following placebo or no treatment is assumed to be 12%, the chance following the use of antioxidants is estimated to be between 14% and 26%. However, this result was based on only 124 live births from 750 couples in seven relatively small studies. When studies at high risk of bias were removed from the analysis, there was no evidence of increased live birth (Peto OR 1.38, 95% CI 0.89 to 2.16; participants = 540 men, 5 RCTs, P = 0.15, I2 = 0%).

Clinical pregnancy rate: antioxidants may lead to increased clinical pregnancy rates (OR 2.97, 95% CI 1.91 to 4.63, P < 0.0001, 11 RCTs, 786 men, I2 = 0%, low?quality evidence) compared to placebo or no treatment. This suggests that if in the studies contributing to the analysis of clinical pregnancy, the baseline chance of clinical pregnancy following placebo or no treatment is assumed to be 7%, the chance following the use of antioxidants is estimated to be between 12% and 26%. This result was based on 105 clinical pregnancies from 786 couples in 11 small studies. Adverse events Miscarriage: only three studies reported on this outcome and the event rate was very low. There was no difference in miscarriage rate between the antioxidant and placebo or no treatment group (OR 1.74, 95% CI 0.40 to 7.60, P = 0.46, 3 RCTs, 247 men, I2 = 0%, very low?quality evidence). The findings suggest that in a population of subfertile men with an expected miscarriage rate of 2%, the chance following the use of an antioxidant would result in the risk of a miscarriage between 1% and 13%. Gastrointestinal: antioxidants may lead to an increase in mild gastrointestinal upsets when compared to placebo or no treatment (OR 2.51, 95% CI 1.25 to 5.03, P = 0.010, 11 RCTs, 948 men, I2 = 50%, very low?quality evidence). This suggests that if the chance of gastrointestinal upsets following placebo or no treatment is assumed to be 2%, the chance following the use of antioxidants is estimated to be between 2% and 9%. However, this result was based on a low event rate of 35 out of 948 men in 10 small or medium?sized studies, and the quality of the evidence was rated very low and was high in heterogeneity. We were unable to draw any conclusions from the antioxidant versus antioxidant comparison as insufficient studies compared the same interventions. Authors' conclusions In this review, there is low?quality evidence from seven small randomised controlled trials suggesting that antioxidant supplementation in subfertile males may improve live birth rates for couples attending fertility clinics. Low?quality evidence suggests that clinical pregnancy rates may also increase. Overall, there is no evidence of increased risk of miscarriage, however antioxidants may give more mild gastrointestinal upsets but the evidence is of very low quality. Subfertilte couples should be advised that overall, the current evidence is inconclusive based on serious risk of bias due to poor reporting of methods of randomisation, failure to report on the clinical outcomes live birth rate and clinical pregnancy, often unclear or even high attrition, and also imprecision due to often low event rates and small overall sample sizes. Further large well?designed randomised placebo?controlled trials reporting on pregnancy and live births are still required to clarify the exact role of antioxidants.

Female, Humans, Male, Pregnancy, Abortion, Spontaneous, Abortion, Spontaneous/epidemiology, Antioxidants, Antioxidants/therapeutic use, DNA Damage, DNA Fragmentation, Gastrointestinal Diseases, Gastrointestinal Diseases/chemically induced, Infertility, Male, Infertility, Male/drug therapy, Infertility, Male/etiology, Live Birth, Live Birth/epidemiology, Oxidative Stress, Oxidative Stress/drug effects, Pregnancy Rate, Randomized Controlled Trials as Topic, Sperm Count, Sperm Motility, Sperm Motility/drug effects, Spermatozoa, Spermatozoa/drug effects

Antioxidants for male subfertility

Roos M Smits, Rebecca Mackenzie?Proctor, Anusch Yazdani, Marcin T Stankiewicz, Vanessa Jordan, Marian G Showell

2019 Mar;

29152370

The title compound, C25H27NO4 (I), the product of the unusual thermolysis of aza­cyclic allene methyl 10,11-dimeth­oxy-3,8-dimethyl-6-phenyl-3-aza­benzo[d]cyclo­deca-4,6,7-triene-5-carboxyl­ate, represents a bicyclic heterosystem and crystallizes in the monoclinic space group P21/c with three crystallographically independent mol­ecules in the unit cell. These independent mol­ecules adopt very similar geometries and differ only in the conformations of the two meth­oxy substituents on the benzene ring. In two of the three independent mol­ecules, both meth­oxy groups are almost coplanar with the benzene ring [the C?C?O?Me torsion angles are 10.8?(2), 12.3?(2), 9.1?(2) and 13.6?(3)°], whereas in the third mol­ecule, one of the meth­oxy groups is practically coplanar to and the other meth­oxy group is roughly perpendicular to the benzene ring, the C?C?O?Me torsion angles being 14.1?(2) and 76.5?(2)°. The mol­ecule of (I) comprises a fused tetra­cyclic system containing two five-membered rings (cyclo­pentenes) and two six-membered rings (piperidine and benzene). The five-membered rings have the usual envelope conformation, with the methyl-subsituted C atom as the flap in each molecule, and the six-membered piperidine ring has a chair conformation. The methyl substituent at the N atom occupies the sterically favourable equatorial position. The carboxyl­ate group lies almost within the basal plane of the parent cyclo­pentene ring [making dihedral angle of 11.68?(8), 18.94?(9) and 15.16?(9)° in the three independent mol­ecules], while the phenyl substituent is twisted by 48.26?(6), 42.04?(6) and 41.28?(6)° (for the three independent mol­ecules) relative to this plane. In the crystal, mol­ecules of (I) form stacks along the b-axis direction. The mol­ecules are arranged at van der Waals distances.

crystal structure, aza­cyclic allenes, thermolysis, microwave synthesis, (epimino­methano)­cyclo­penta­[a]indene, 3-benzazepine, synchrotron X-ray diffraction

Unusual thermolysis of aza­cyclic allene under microwave conditions: crystal structure of (3RS,3aSR,8RS,8aRS)-methyl 5,6-dimeth­oxy-3a,10-dimethyl-1-phenyl-3,3a,8,8a-tetra­hydro-3,8-(epimino­methano)­cyclo­penta­[a]indene-2-carboxyl­ate from synchrotron X-ray diffraction

Le Tuan Anh,a,* Alexander A. Titov,b Maxim S. Kobzev,b Leonid G. Voskressensky,b Alexey V. Varlamov,b Pavel V. Dorovatovskii,c and Victor N. Khrustalevd

2017 Oct 24